I have no idea what is wrong with Windows Movie Maker please help

I have been making this video for a while and it has taken me a long time/effort. I cannot play or edit it. I used another video with music in the audio section to see if it would work and now I cannot delete it and my video will not play. It keeps not responding and crashing. I went onto the control panel and came up with this info about the issue:
Problem signature
Problem Event Name: AppHangB1
Application Name: MOVIEMK.exe
Application Version: 6.0.6000.16386
Application Timestamp: 4549b5b6
Hang Signature: dd9f
Hang Type: 16385
OS Version: 6.0.6001.2.1.0.768.3
Locale ID: 2057
Additional Hang Signature 1: 70ff1b221ec7cb9f723bf7d589176fe3
Additional Hang Signature 2: cd4c
Additional Hang Signature 3: 5ace4781dfcd9775b8d246241bef7da2
Additional Hang Signature 4: 169c
Additional Hang Signature 5: e7c38b90470e8d8d19f1c48193a1fe9d
Additional Hang Signature 6: b773
Additional Hang Signature 7: 15d47080cfdc8363a947661376552799

Extra information about the problem
Bucket ID: 55713666

I'm not sure if that helps or not. I have no idea what to do and I don't want to use another program to try and start again. I have divx condecs but I don't know if they are causing the problem. I have a pretty good graphics card ect. As you can see I'm not that good with laptops so any simple help would be greatly appreciated thanks